Aircraft



E. A. STALKER 2,084,464

AIRCRAFT Filed Oct. 28, 1955 June 22, 1937.

6 Sheets-Sheet 1 7 Jun? 22, 1937. E. 4.. STALKER 2,084,464

AIRCRAFT Filed Q01 28, 1935 6 Sheets-Sheet 2 June 22, 1937. E. A. STALKER AIRCRAFT Filed Oct. 28, less 6 Sheets-Shet s mWEA/ TOR awn/2% Jun 1937..

E. A. STALKER AIRCRAFT Filed Oct. 28, 1955 6 Sheets-Sheet 4 FIG l8 Q MMM June 22,1931. I E. ,1; STALKER ,0 4,464

AIRCRAFT Filed Oct. 28, 1935 6 Sheets-Sheet 5 @Wmm FIG l3 Ju ne 22, 1937.

E A. STALKER AIRCRAFT Filed Oct. 28, 1955 l s Sheets-Sheet e v\ QR v Patented June 22,- 1937 I line Ila-l lain Figure 11;

UNITED STATES Pram OFFICE AIRCRAFT Edward A. Stalker, Ann Arbor, Mich. Application October 28, 1935, Serial No. 47,131

6 Claims.

My inventionrelates-to aircraft, particularly rotary wing aircraft, and it has for its objects;

first, to provide boundary layer means of suppressing the lateral dissymmetry in lift arising from differences in relative air velocities; second, to provide means of lateral and longitudinal control by tilting the axis of rotation of the wing system; third, to provide directional control deriving power from the autorotation of thewing system; fourth, to provide an aircraft which is controllable about any axis under any condition of flight, is free from lift and gyroscopic unbal- V ance and has power means to rotate the wings.

I havefiled previous applications which have subject matter in common with this application, namely, Serial No. 695,149 filed October 25, 1933, Serial No. 699,885 filed November 27, "1933, and Serial No. 29,476 filed July 2, 1935 respectively.

I accomplish these objects by the devices illustrated in the accompanying drawings in which- Figure l is a side elevation of the aircraft;

Figure 2 is a top plan view of the aircraft partly in section; I

Figure 3 is a front elevation of the aircraft;

Figure-4 is a fragmentary part section of the aircraft along the line 44 in Figure 2;

Figure 4a. illustrates the cylinder and piston used in the control system;

Figure 5 is a fragmentary part section along the line 5-5 in Figure 2;

Figure 5a is a side elevation of the valve used in the control system;

Figure 5b is a section of the valve along the line 5b5b in Figure 5a;

Figure 6 is a fragmentary vertical part section of the wing portion near the hub;

Figure '7 is a vertical section along the line l-l in Figure 6;

Figure 8 is a fragmentary part section of the shaft length adjuster;

Figure 9 is a cross section of the adjuster along line 9-9 of Figure 8;

Figure 10 is a fragmentary part section of the hub along the line I -l in Figure 11;

- Figure 11 is a fragmentary side elevation of the hub;

Figure 11a is a part section of the hub along Figure 12 is a top plan view of a wing without the hub element;

Figure 13 is a vertical chordwise section along the line l3-l3 of Figure 12;

Figure 14 illustrates the preferred form of the wing and related structure and is a fragmentary part section along line l4l4 in Figure 2;

- of length of the curve.

vation of the preferred form taken along line Iii-I in Figure 2;

Figure 16 is a fragmentary top plan view of a Figure 17 is a vertical chordwise section taken along line l'|l| in Figure 16;

Figure 18 is a vertical section along line I8- l8 in Figure 16;

Figure 19 is a fragmentary elevation of a valve fork;

But in the boundary layer the fluid has lost momentum and it is possible for the fluid of the layer to reverse its direction and move upstream with resulting turbulence and separation of the main stream from the wing surface. The lift decreases and the drag increases under these conditions.

If energy is added to the boundary layer it will not reverse its direction. of flow and the high drag can be avoided. One means of adding energy to the layer is to form a slot in the body surface to emit fluid rearward substantially tangentially to V the surface. The slot is in communication with the'body interior and a means of blowing is employed to supply the fluid jet.

Besides energizing the boundary layer and increasing the lift the jet can also increase the lift by increasing the circulation about the wing section. It is well known in the science of aerodynamics that'the lift can be explained as the resultant of two components of flow about the wing cross section. These components are the rectilinear flow due to the advance of the wing,

and the circulation. The latter is defined as the integral of the velocity. along any closed curve enclosing the wing and the differential Blowing out a slot inicreases the circulation velocity andif the jet is directed rearward on top of the wing an increase Figure 20 is a side elevation of a portion of the control mechanism isolated from the aircraft. 1

' thereto.

duced and the lift decreases. I use bothan upper and a lower surface slot to control the lift on the wings and thereby suppress dissymmetry of lift and provide steering control.

The wings system is comprised of wings pivoted for oscillation in the plane of rotation and normal Tilting of the shaft upon which the wings are I supported has been used before but in the former instances each blade was hinged to a hub so that there was an appreciable distance between the hinge axis and the axis of rotation of. the wing system, that is, the shaft axis. This was always true for at least one of the hinge axes, either that for vertical-or horizontal oscillation and usually for both. The offset of the hinge axis from the axis of rotation causes roughness in the'operation of the wing system which is unpleasant to.

the passengers and dangerous to the structure.

"The. oflset of the hinge for vertical oscillation served oneuaeful purpose, however. When the shaft or axis of the wing system was tilted the wings shifted their paths of rotation automatically. This effect will be clear from the following illustration; Let there be'no lift on the wings so that they are perpendicular to a shaft and its axis of rotation and hinged with an ofl'set of the hinge axis from the axis of rotation. If the axis is tilted the elements of the blade are not .84: their maximum position from the axis and hence move outward until' the blade is again perpendicular to the axis. Now consider the case where the wings are attached to the shaft by a ball and socket joint so that they are free to move in any angular direction. Let the wings be rotating and tilt the-shaft. The wings will not change their paths of rotation since there is no means of changing the axis of rotation. The

wings are free onthe ball. In this case, if'thc' paths of wings are to be changed'the lift onthe a ring shaped inner end while the-third "wings-should be changed to move the wings. I

do this through controlling a jet flow through slots in the wing.

Referring particularly to Figures 1 to 3 the wing system is W, the fuselage is Lthe horizontal tail is I, and the landing ear is 3. 1

The wing system W supports the aircraft and is composed of the three wings 4, 5 and 6. The wings are supported in the hub socket 1 (see Figures 4 to 11) so that they have a common center of oscillation. The manner in which'this support is accomplished is best illustrated in Figures 6, l and 11. Each wing has a hub-element 8 fixed in the wing. Two of these elements have spherical end recessed to accommodate one of the rings. The conjunction ofthe ends of the hub elements is shown in' Figure 10.' The element 8 has the recessed spherical end. The element 8a is borne on the recessed portion 9 of element 8. f

The element 8b is borne on the element 8. These hub elements all have free limited motion relativeto each other since all the bearing surfaces are spherical inform and the. elements, have run- Since the wings are free of structural restraint stopping their vertical oscillation relahalves together.

hasa' inlift results. If the jet is directed rearward onthe lower surface a negative circulation is in-- ning clearances. It will now be clear. that all thewings to which the hub elements 8, 8a, 8b

attach are free to oscillate about a common center in both vertical and horizontal planes, a rubber block |a'Figure 11ais inserted in the hub socket 1 about each hub element 8 to absorb the shock of limiting the oscillation of the wings.

The angular oscillations of the hub elements are limited by the apertures III, II and 12 in the hub Socket 1. This socket is formed in two halves having flanges I3. Bolts (not shown) through 'the flange holes l4 serve to fix the two The ring end. of hub element 8b bears on the inner'surface of the hub socket.

Again, since all surfaces concerned are spherical, there is freedom for relative universal motion between the parts.

As shown in Figure 10, the ring of element at is split diagonally along line so that it can be assembled over the end of element 8. A number of studs with recessed heads serve tohold the two parts of the element together. One of these bolts I1 is shown in Figure 10. I

The hub socket I is "supported through the hub shaft l8 which is integral at its upper end with the hub socket, Rigidly fixed t6 shaft I8 is the bearing plate It! supported on the aircraft' by the tripod frame F composed of upright members 28, 2i and 22. '(See Figures 4 and 5.) .The bearing plate is supported by the balls 23 for universal rocking and for rotation about the axis of shaft l8. A'removable jacket 24 restrains the bearing plate against upward thrust. That is, the jacket 24 transmits the lift of the'airscrew to he aircraft by virtue oflts attachment to the tripod frame F. The studs or bolts attaching the jacket to the frame are not shown.

Enclosing the hub socket and the inner ends of the wings-is the casing head 25 which has as many openings 26 as there are wings. The casing head is in part spherical, namely, at the'inner surface about the openings 28. Thus any oscilla-' tion of the wings about the center of the hub socket is such that a sealingplate 21 can be kept in contact with the inner surface of the casing head.

' In normal operation under power air isblown up the conduit 28 by the'blower 29 into the casing head 25 from whence the air enters the wings W, for instance; wing 5 in Figure 4. The/sealing plate fl prevents fluid from escapingout the holes 26. The air enters the inner end' of the wing and proceeds through the hollow interior. to the slot 5a which is rearward directed, that is, directed to discharge the air toward the trailing edge of the wing. ticularly.)

The fluid jet discharged from the slot will decrease the lift by energizing the boundary layer and if the jet flowv is properly controlled the vertical oscillation of the wings can be suppressed. A pair of valves 30, Figures 4, 6 and 7, control the flow to the wing interiors. These valves are airfoil shaped preferably and are positioned on each side of, the vertical end of element 8. The valves are pivoted for oscillation about the axis of the horizontal pivot 31. 1 Ai'orked link 32, Figure 4, connects the forward end of each valve to an (See Figures -7, 12 and 13', pararm 33 rigidly fixed to the hub socket 1. It will now be clear that a vertical movement of the wing will cause an oscillation of the valves 30.

Since the distance between the front edge of the wing and the front edge .of the valve the angular to the angular change in the wing. Hence there can be a great change in the flow out of slot 5a in the wing for a small vertical oscillation of the wing.

The valves and their linkages are arranged so that an upward swing of the wing will admit more air to the wing interior and the slot 5a so ill Iii

that the lift is decreased. A downward, swing of the wing will reduce the air flow and give a higher lift to the wing. The theory of this has been previously discussed. Since each wing is equipped with valves 30 and the proper linkages 32 each wing independently controls the fiow to its surface slot.

The casing head 25 is free to rotate relative to the conduit 28 by virtue of the joint at 34. The

ring 35 which is made in two parts holds the casing head on the conduit 28. V

The wings drive the socket 1 and the shaft 18 when the blower ceases to send air into the wing interiors, as for instance, if the engine 35 failed to function. The autorotation property of helicopter wings is well known.

I provide for directional control by means of a propeller 31, Figures 1 and 2, positioned in an opening 31a in the tail of the aircraft, and I make its rotation dependent on the rotation of the wings so that I have directional control even when the engine fails. I also provide means to operate the directional control in conjunction with the roll and pitching control.

The propeller 31 is actuated by the helical gears 38 of which one is on the shaft 39; This Shaft39 is driven by the wings through the shaft I8, bevel gears 40 and 41, shaft 42, universal joints 43 and 43a. shaft 44, and extension joint 45. v

Since the'propeller 31 is positioned at a definite locality on the aircraft .and since shaft I8 is oscillatable universally, the driving mechanism between shaft I8 and the propeller 31 must be accommodated to the movements of the shaft 18. The shaft 39 is supported in suitable bearings such as 46 and has no longitudinal movement, only rotary movement. When the shaft 18 is pushed forward or rearward the movement is accommodated by the expansion .joint which is also shown in Figures 8 and 9. 'It consists of a splined plunger 45a on the end of shaft 39 and a grooved cylinder 45b on the end of shaft 44. The splines and grooves permit axial: sliding of the two parts and provide means to-transmit rotary motion. Angular accommodation is secured through the universal joints 43 and 43a. This is a well known element and its details need not be given. I

The alignment of the bevel gears 40 and 4| is secured by the housing 41 which is free to rotate on the shaft 18 and carries the bearing for the shaft 42. .The opening 28a in the conduit is large enough to permit a sufficient annular swing of the shaft 42. The opening is sealed by a fabric bellows to prevent fluid leakage.

It will now be clear that the wings operating in an autorotative state can rotate the propellcr 31. The propeller 31 is adjustable for pitch through positive and negative values, so that a force can beprovided in either direction. I do not describe the pitch changing device since this is well known and is now procurable on the market. The control of the pitch. can be placed near the pilot and preferably should be connected to the rudder pedals.

The rolling and pitching of the aircraft is accomplished through the oscillation of shaft 18.

If, for instance, this shaft is pushed forward at I the lower end the valve 30 will be rotatedrelative to the wings which tend to maintain their normal path of rotation. The valves are moved because thehub socket 1 moves with the shaft l8 andthe am 33 and link 32 depress the forward edges of the valves of the wing extending rear- 1 ward. The valves of the forward extending wings eremoved in the opposite direction. It will be apparent that a downward movement of the,

valves of the rearward wing will admit more air to the lower surface slot and decrease the lift of the wing: On the other hand, less air'will be admitted to the forward extending wing and so these wings will drop. In other words the mean path of rotation of the wings will be inclined downward in front; or the axis of rotation of the wings will be inclined forward at the top.

If the aircraft was in balance before the movementof the shaft 18, the line of action of the lifting force went through the center of gravity of the machine. If new the rotation axis of the wings is tilted forward at, the top the lift force will pass to the rear of the center of gravity and the airplane will be-rotated as for-a dive. A movement of shaft 18 to the rear will cause the aircraft to pitch up at the nose.

A lateral movement of the shaft ill will tilt the path of rotation of the wings so that the lift force passes to one side of the center of gravity whichwill cause a roll of the aircraft, the top of the machine rotating toward the low side of the path.

Thus it is clear that a tilting of the shaft l8 universally will control the rolling and pitching of the aircraft.

I prefer to move the lower end of shaft I8 by fluid pressure operating upon pistons connected by a suitable linkage system to the end of shaft 18. (See Figures 4 and 5.) For instance, to provide a forward movement of the end of shaft I8 I employ the cylinder 48 having a piston 49 within. (See Figure 4a.) nected to the bearing ring 51 on the end of shaft l8 by a universal joint 52. The bearing ring is free to turn on shaft 18 to accommodate the universal movement of the shaft. The rear end of the cylinder is attached to the blower 29 by the universal joint 53. The cylinder could, of course, also be attached directly to the structure of the aircraft.

The piston in the cylinder is moved by fluid All The piston rod is conpressure supplied through the tubes 54 and 55. v The fiuid passes through atwo-way valve 56 un- The shaft 18 is moved laterally by a mechanism like that for longitudinal control. It cons sts of the cylinder 51, rod 58.and appropriate universal joints 59 and 60. The valve 6! and tubes 62 and 63 convey the fluid to and from the cylinder. 7

Fluid under pressure is supplied by the gear pump 64 driven by gears 65 and 66, of which the latter is fixed on the shaft 39 so that the wings can drive the pump and make the control of the aircraft dependent on them and independent of the functioning of the engine 36. Other types of pumps can be used if desired. The pump is supported on the aircraft structure. The tubes Details :of the interiorjof a valve. are shown in Figures fia and b. The valve caseis. 89 and 5 the valve rotor is 18. The rotor is rotatably borne on the tube ,II which extends. the depth ofthe casing interior and is ported in two places lla .and Nb. The rotor also'has two ports 18a and I817.v When fluid is being sent from the inlet tube 4 j tothe tube 54 going to one end of the cylinder,

the rotor part 180 normally does not exclude entirely the access of the incoming fluid to the.

tube 55 and the ports 10a and Ha. Rather, fluid from both tubes 55 and 51 has access to the ports 18a and Ila. By permittinglea'kage past 18c a more sensitive control is obtained for the cylinders 48 and 51' and also one that provides a movement of the piston 89 to a position in accordance with the stick position. 20 Control of the valves is exercised through a conventional control mechanism of which the torque tube and push tube 18 are shown in Figures 4 and 5. A rotation of the torque tube 15 rotates the valve arm 14 by means of the link 18 and arm l9.v (See Figure 5 particularly.) The push-pulltube 16 (Figures 4 and 5) operates the bell crank 88, link 8I and valve arm 14a.

The torque tube and control stick with connect1'ng members is shown isolated from the aircraft in Figure 20. The stick is 82 and is pivoted at 83 for fore and aft rocking. The tube 16 is pin connected to the lower end of the stick.-

If the control is traced it will be found that a forward movement oil the top of the stick causes the aircraft to dive while a lateral stick movement causes the aircraft to roll in the same direction. Thus the stick movement and the maneuve'rs of the aircraft are according to present conventions. e I

In Figures 14' to 19 I illustrate a more complicated form of the wing arrangement and the means of supplying them with fluid. 'I'hese give the form I prefer. The external view of the aircraft is the "same as previously described and so the Figures 1, 2 and 3 serve to indicate the localities of the various section drawings.

Referring particularly to Figures 14 to 1'7, it will be observed that the hub socket 88 and shaft 85 are definitely positioned with respect to the aircraft structure." That. is, the. shaft '85 can rotate about its axis but it is not tiltable aslwas shaft I8 in Figures 4 and 5. The shaft 85 is rotatably supported on the thrustball bearing 88 and the radial ball bearings 81. The bearings are in turn supported by the frame F.

- The wings, Figures 16 and 17,. have both-upper and lower surface slots with a partition 88- to divide the wing interiorinto two compartments each associated with one of theslots. Thus slot 89 is in communication with the forward oompartinent 98 and the slot 9I is in communication with compartment 92. The partition 88 is vertical for the major portion. of the span but is. twisted to become'horizontal at the root of the wing, asindicated in, Figure 16. The element 8 is still vertical and serves to securethe wing to. the hub socket 88 which is identical with the socket I except for the omission of the arm .33. On either side of the element 8 are positioned the valves 93 which are hinged at their outer ends to the partition 88 by a pin'at 94. A rotation of the valves about their pins deflects the air to a greater extent into one of the wing compartments 98 and '92 so that the flow to the ":upper and lower surface slots are controlled differentially.

.push-pull tube 18 for longitudinal control.

hinged to the casing head 91.

and 14a. The prongs of the forked lower end fit A flow out the surface slot will increase the lift of-the wing while a flow out the lower I surface slot will decrease the lift.

I The valves 93 are normally held in a'defl'n'itej position relative to the aircraft by the forked links 32:; which have ball [and socket Joints at each end. A movement ofa wing; upward will rotate the valve relative to the wing in such amanner as to admit more fluid to compartment 92 and less air to compartment 98 so that the lift of the wing is decreased. That is, the com.-

partment 92 is in communication with the por-' tion of the wing inlet above the valves 93. It is clear from Figure 16 that the partition 88 is twisted to provide such communication.

The valves 93. can be operated by the pilot through the control mechanism. The links 32a extend downward and connect to a hollow spherical segment or control ring 95 which is universally supported onball bearings by the spherical surface 98 formed inside the casing head 91. The control ring '95 can be rocked by the control mds 98, 99,188, and IN, shown in Figures 14 and 15. These rods have ball and socket joints I82 at their upper ends which attach to the ring ro-.

tatably borne in the control ring 95.

That is,

the ring 95 rotates with the'wings about their common axis while ring I83 does not rotate about that axis. l

- Control of the rocking of the control ring is accomplished through the bell crank I84 and In lateral controlthe torque tube 'I5 andarm 19, Figure 15, link I1, auxiliary lever 11a and, link 11b tilt the rocker arm I85 to which the control rods I88 and MI are attached. It will now be clear that a movement of the control stick. can cause lateral and longitudinal tilting of the control ring 95.

,A tilt of the control ring rotates all the valves simultaneously and varies the lift of the wingsso that their mean path is tilted and causes the lift force to pass to one side of the center of gravity of the machine as described earlier.

4 The conduit 28c conducts the fluid from the i hub socket 84 and rotates with the wings. The Joint between the conduit 28c and the head is sealed by the sealing ring I8], Figures 14' and 15. There are three forked arms 910 which are See Figures 14 slideably over the elements 8a,'8b, and 80, re-

spectively. The slot between the prongs permits the upward oscillation of the wings while the hinge at the upper end permits the wings to oscillate in a. horizontal plane. At the same'time the wings are restrained from any extreme roll- .ing about a spanwise axis which would change the angles of attack of the wings unduly. The change in the angles is such as to reduc'ethe vertical oscillation since when driven the advancing wing will lag more than'the, retreatingwing.

Air for the blower 29 is takeninto the fuselage side of While I have illustrated a preferred form ofthe invention it is to be understood that I do not limit myself to these exact forms and constructions but intend to claim it broadly. It will be clear to those skilled in the art that changes and modifications can be made in it without departing from the spirit or scope as defined in the appended claims.

I claim:

i. In an aircraft in combination, a body, a direct lift system to sustain the body comprising a plurality of hollow wings rotatable about an upright axis and oscillatablerelative thereto, a plurality of said wings having an opening in the wing surface directed rearward and in communication with the wing interior, means of blowing in communication with the wing interiors to induce a rearward blast of fluid through said openings, and substantially independent valvular means for each wing having a said opening to regulate the flow from each wings respective opening, said valvular means being governed by the oscillation of same said wing receiving the. flow through said valvular means, each valvular means being operable substantially independently of the other valvular means.

, 2. In an aircraft, a direct lift system: to sup port the aircraft including at least two hollow wings rotatable about an upright axis and oscillatable relative thereto, each of said Wings having a spanwise slot in its lower surface in communicatior with the wing interior and directed rearward with respect to the Wing's direction of rotation, a blower means in communication with the Wing interiors to induce a rearward flow out said slots to rotate the wings by the momentum reaction of the discharged fluid, and automatic valvular means for each wing to control the slot flow in accordance with the angular position of said wing relative to the aircraft to provide chiefly favorable vertical momentum reaction forces on the oscillatable wing, said valvular means including a streamline vane pivoted for oscillation by its respective wing.

3. In an aircraft, in combination, a body, a direct lift system including a plurality of wings rotatable about an upright axis, ball and socket supporting means to mount said wings on the body for oscillations relative thereto about a point as a common center for at least three of the wings and providing for the oscillations of each of the said three wings about said center and about axes transverse to its wing span substantially independently of each other with respect to bothvertical and horizontal oscillations and means to restrain the wings against changes in the pitch angle beyond a predetermined range of angles.

4. In an aircraft in combination a plurality of wings having hollow interiors and rotatable about an upright axis and oscillatable relative,

thereto, each wing having a spanwise slot in its surface in communication with its hollow interior,

'means of blowingin communication with said hollow interiors to induce outward flows through said slots to alterthe lifts of the wings, an oscillatable valve for each wing to control the flow through its slot to alter the lift of the wings unsymmetrically to achieve a balance of the aircraft'against upsetting moments, a mechanism interconnecting the wing and its respective valve to oscillate it to control the flow to the wing slot, said mechanism being adapted so that for a given angle of oscillation of a wing the valve associated with said wing is moved through a larger angle by the oscillation of the same said wing.

5. In an aircraft in combination a direct lift system including a plurality of wings rotatable about an axis and oscillatable relative thereto, each said wing having a hollowipterior and a slot in the surface leading into its hollow interior, each slot extending spanwise for use in altering I the lift of the wing, a means of blowing in communication with said hollow interiors to induce a flow through said slots to alterthe lift of the wings, valve means including a movable valve element for each wing to control the flow through its respective slot, each said. valve means being operable substantially independently of the valve.

rior and a slot in the upper surface of the wing in communication with said interior, a valve for each wing to control the flow through its slot, and a mechanism having an element movable by the oscillation of the wing to operate the valve to supply a flow of fluid to the slot of the associated wing when said wing is descending in its oscillation, the flow through said slot of the descending wing serving to increase the lift of said wing and reduce its downward travel.

EDWARD A. STALKER. 

